The present invention relates generally to drafting instruments and particularly to rulers for use by calligraphers for laying out borders, margins, centerlines, guidelines and the like.
A variety of drafting and other special purpose rulers have been used over a number of years, but none of these instruments is specifically suited to the work of a calligrapher, whose craft has a variety of special requirements. Typically, a calligrapher will use several separate instruments, such as a centerline ruler, a T square, standard inch and metric rulers and drafting triangles, to lay out his work. Such use of multiple instruments is inconvenient, time consuming and frequently leads to unnecessary inaccuracies in the work.
Some more sophisticated instruments have included one or more fixed scales of numbered indicia that commence at one end of a T square-type ruler. While such devices may be suitable for many purposes, they do not substantially facilitate centering of work on a page nor can they be used efficiently to draw lettering guidelines on a page without the simultaneous use of multiple instruments. This is because the scales which they contain are preestablished at fixed locations and because the scales include indicia set at fixed intervals which may or may not be convenient for calligraphic work. Since the scales are immovable and contain fixed uniform indicia, frequently the indicia will not happen to register with the guidelines the calligrapher intends to draw.